In the machine tool, in order to prevent the tool from interfering with other parts, the operation of the tool may be limited. For example, JP Patent Publication No. 60-160407 and JP Patent Publication No. 2008-234295 disclose that the limit (minimum and maximum values) in a moving axis direction is set and when the tool movement exceeds the limit value in manual machining operation, the manual operation is stopped.
Further, according to JP H4-71202 B2, by setting a workpiece interference region corresponding to the position of the outer surface of the workpiece, whether or not a tool is entered into the workpiece interference region is detected.